#! /bin/bash
echo "输入成绩"
read num
num=$((num/10))
case $num in
10 | 9)
	echo "A"
	;;
8)
	echo "B"
	;;
7)
	echo "C"
	;;
6)
	echo "D"
	;;
*)
	echo "不及格"
	;;
esac

